Carbosulfan

Description

Carbosulfan (8)，2,3-dihydro-2,2-dimethylbenzofuran- 7-yl(dibutylaminothio)methylcarbamate(IUPAC), is an orange to brown, clear viscous liquid (bp 124–128 ?C), miscible with organic solvents and solubility 0.3 ppm in water(25 ?C). It is closely related structurally to carbofuran,and like carbofuran, it is a cholinesterase inhibitor with systemic activity.

Chemical properties

Orange-yellow thick liquid.

The Uses of Carbosulfan

Carbosulfan is an insecticide with contact and stomach action. It is used to control a wide range of soil-dwelling and foliar pests in cotton, sugar beet, potato, rice, fruit, maize, vegetables, sugar cane and coffee.

Definition

ChEBI: Carbosulfan is a member of 1-benzofurans and a carbamate ester. It has a role as an EC 3.1.1.7 (acetylcholinesterase) inhibitor, a carbamate insecticide, an acaricide, an agrochemical and a nematicide.

General Description

Viscous brown liquid.

Air & Water Reactions

Thio and dithiocarbamates slowly decompose in aqueous solution to form carbon disulfide and methylamine or other amines. Such decompositions are accelerated by acids.

Reactivity Profile

Carbosulfan is a thiocarbamate. Flammable gases are generated by the combination of thiocarbamates and dithiocarbamates with aldehydes, nitrides, and hydrides. Thiocarbamates and dithiocarbamates are incompatible with acids, peroxides, and acid halides.

Potential Exposure

Carbosulfan is a carbamate insecticide and a low toxic derivative from cabofuran. It is a broad spectrum insecticide, nematicide, miticide, effective against pests and mites. It is used to protect alfalfa, apple, citrus, corn, deciduous fruit, potato, rice, sorghum, soybean, sugar beets, sugarcane, and other vegetable, field, tree and orchard crops. It is used for seed treatments

Metabolic pathway

Carbosulfan is an N-sulfenyl-N-methylcarbamate which is effectively a pro-insecticide of carbofuran. The latter is formed in vivo by the biochemical or chemical thiolysis of carbosulfan. N-S Bond cleavage, oxidation, conjugation and hydrolysis are the main metabolic routes for carbosulfan in plants and animals. Carbosulfan is degraded via carbofuran in soil. In plants, carbosulfan is metabolised via carbofuran to 3-hydroxycarbofuran (PM).

Metabolism

Itsmetabolic patterns are similar to those of carbofuran. In rats, it rapidly undergoes hydrolytic and oxidative processes followed by conjugation. It is not persistent in soils, with DT₅₀ ca. 2–5 days, and it was rapidly degraded to carbofuran in a sandy loam soil (4). Carbofuran was subsequently hydrolyzed at the carbamate ester group to form the phenol carbofuran or oxidized at the 3- position. Biscarbofuran disulfide and minor products were also detected. Carbofuran was also formed in soils by nonbiological degradation processes.

Shipping

UN2992 Carbamate pesticides, liquid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials; UN2810 Toxic liquids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required.

Degradation

Carbosulfan is hydrolysed in aqueous media most rapidly under acidic conditions. Its DT₅₀ values (25 °C) at pH 4,6 and 7 were <1 hour, 22 hours and 7.6 days respectively (PM). In a variety of aqueous solvents there was facile cleavage of the N-S carbamate bond of carbosulfan to yield carbofuran (2) as the sole or major product (see Scheme 1) (Umetsu et al., 1980). A solution of [¹⁴C]carbosulfanin propylene glycol was treated with 0.001 or 0.01 N aqueous HCl at 40 °C. Solutions were analysed at intervals up to 24 hours. Carbosulfan was relatively stable with more than 40% being recovered after 24 hours in the solution of lower acidity. Carbofuran (2) was the principal transformation product in hydrochloric acid. Biscarbofuran disulfide (3) was present in only trace amounts and small amounts of polysulfides of carbosulfan (4,n = 2-6) were detected (Umetsu and Fukuto, 1982).
Carbosulfan was quite stable in neutral and alkaline media. [¹⁴C-carbonyl]- or [¹⁴C-dibutylamino]Carbosulfan dissolved in dichloromethane: acetic acid (9:l) converted to a range of products via N-S bond cleavage. The principal products were carbofuran (2), dibutylamine and a mixture of polysulfide derivatives: bis-carbofuran disulfide (3) and a mixture of bis-carbofuran polysulfides (5). Structures of products were confirmed by MS and NMR (Umetsu et al., 1981a,b).

Incompatibilities

Carbamates are incompatible with strong oxidizing acids, peroxides, and hydro-peroxides; strong reducing agents such as hydrides; strong acids and bases. Contact with nitrides or chemically active metals (aluminum, copper, magnesium, neptunium, sodium, tin, titanium,zinc, etc.) causes the release of potentially explosive hydrogen gas and a metal salt.

Waste Disposal

Do not discharge into drains or sewers. Dispose of waste material as hazardous waste using a licensed disposal contractor to an approved landfill. Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Incineration with effluent gas scrubbing is recommended. In accordance with 40CFR165, follow recommendations for the disposal of pesticides and pesticide containers. Noncombustible containers should be crushed and buried under more than 40 cm of soil. Must be disposed properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office.